Hi Max,
that sounds pretty cool. I have a lot of narrow gauge tracks, switches and crossings here, but I just played around with them a little bit – nothing serious yet. I didn’t have time to get into the science of building rolling stock for narrow gauge yet, so I have no practical experience in that yet. But I have a strong desire to dive into that matter later. So, maybe I ping you one day for exchanging a bit more of your experience.
Did you check out the track planning section on Mattzobricks yet? I have added narrow gauge tracks to the Trixbrix library for Bluebrick, so Track Planning should be quite easy also for narrow gauge.